Polls have provided empirical data to this trend in the key battleground states of Minnesota and Colorado, where Rick Santorum has emerged as the clear conservative alternative to moderate Mitt Romney.

And just as important as the General Election horserace is, Rick Santorum is proving to be the most popular and likeable Republican candidate for President – a key ingredient to winning not just elections, but the hearts and minds of voters. (Public Policy Polling)

The conventional wisdom tells us Mitt and Newt are the only choices in this race. But these most recent polls clearly suggest that Santorum, not Newt, is the strongest conservative alternative. I’ve carefully and candidly laid out the strengths, weaknesses, and best arguments for Santorum. I’m working in my home state of Colorado to spread the message. Ed Morrissey makes his case for Santorum to his fellow Minnesotans and the Right at Hot Air. David Limbaugh did last week. More support from the Right spotlighted here by Stacy McCain.

Is it a long shot? Yes. Is it doable? Yes. There are no inevitabilities in politics.

Santorum’s got game. Strong showings in Missouri, Minnesota, and Colorado could bring the fundraising boost he needs. You can help right now right here.

Mr. Santorum is, in many ways, a more dangerous opponent for Mr. Romney than Mr. Gingrich at this point. He has run a more disciplined campaign than the former House speaker, has less personal baggage and is less disliked by party leaders.

Mr. Santorum can also make a credible claim to challenging Mr. Romney on electability. Mr. Santorum’s current unfavorable rating among all voters is 11 points lower than Mr. Romney’s, 36 percent versus 47 percent. Their favorable ratings are roughly equal: 30 percent for Mr. Santorum to 29 percent for Mr. Romney.

Mr. Santorum’s conservative positions on social issues might not make him an ideal fit with certain types of independent voters. States that are moderate to -liberal on social policy, like Virginia, New Hampshire, Nevada and Colorado, could be tougher for Republicans to win if Mr. Santorum is their nominee.

But those concerns might be outweighed if Mr. Santorum shows strength in the Midwest — and Mr. Romney shows weakness.

…With Mr. Santorum, however, you can at least draw up a coherent path to victory, one that runs through the Midwest. There is a Midwestern state left to vote at virtually every turn of the nomination calendar. After Michigan on Feb. 28 and Ohio on Super Tuesday comes Missouri (again) on March 17, when it holds its caucuses, then Illinois on March 20, Wisconsin on April 3 and Pennsylvania on April 24. (A big disadvantage for Mr. Santorum: He did not qualify for the ballot in Indiana, which votes on May 8.)

Mr. Santorum would eventually need to expand his coalition beyond the region — such as to the socially conservative states of the South. But victories for him in Minnesota or Missouri — especially if he wins both — would at once raise new concerns about Mr. Romney’s appeal to working-class voters and make Mr. Gingrich’s victory in South Carolina appear to be a one-off event that is quickly receding in the rear-view mirror.